Surgical instrument and steering gear for same

Abstract

A steering gear for a surgical instrument includes two motorized drives designed to spatially align a wobble plate via the adjustment angle of the two drives, which is designed to control a distal angling mechanism of the surgical instrument. A first of the two drives has a first motor, which drives a drive pinion via a driveshaft, which engages with a lateral toothing of a first toothed rack, driving a first transmission pinion of a first double gear. A second of the two drives has a second motor driving a drive pinion via a driveshaft, which engages with a lateral toothing of a second toothed rack and drives a second transmission pinion of a second double gear wheel. The wobble plate is arranged between the two bevel gear rims, which are facing one another and lie on a common axis.

The invention claimed is: 
     
         1 . A steering gear for a surgical instrument, the steering gear comprising:
 two motorized drives configured to spatially align a wobble plate by way of the adjustment angles of the two motorized drives, the wobble plate being configured to control a distal angling mechanism of the surgical instrument, wherein   a first of the two motorized drives includes a first motor which drives a first drive pinion via a first drive shaft, said first drive pinion meshing with a first lateral toothing of a first gear rack and driving a first transmission pinion of a first double gear wheel made of the first transmission pinion and a first bevel gear rim via a first end toothing of the first gear rack, and   a second of the two motorized drives includes a second motor which drives a second drive pinion via a second drive shaft, said second drive pinion meshing with a second lateral toothing of a second gear rack and driving a second transmission pinion of a second double gear wheel made of the second transmission pinion and a second bevel gear rim via a second end toothing of the second gear rack, and   wherein the wobble plate is arranged between the first bevel gear rim and the second bevel gear rim which face one another and are located on a common axis.   
     
     
         2 . The steering gear as set forth in  claim 1 , wherein the respective orientations of a first and second drive axis of the corresponding first motor and the second motor are definable independently of one another and in relation to a plane defined by the longitudinal axis and the common axis, wherein a toothing of the corresponding first and second drive pinions with the respective first and second lateral toothings is formed depending on the orientation of the respective first and second drive axis,
 wherein the first drive axis of the first motor is preferably present parallel to the second drive axis of the second motor, wherein the first and second drive axes run perpendicular to the plane defined by the longitudinal axis and the common axis, and wherein the first and second drive pinions preferably form a spur toothing with the first and second lateral toothings.   
     
     
         3 . The steering gear as set forth in  claim 1 , wherein the wobble plate is coupled to a third gear wheel which meshes with the first and the second bevel gear rims of the first and the second double gear wheels and whose axis of rotation is at right angles to the common axis of rotation of the driven first and second double gear wheels. 
     
     
         4 . The steering gear as set forth in  claim 1 , wherein the wobble plate is coupled to a fourth gear wheel which is coupled to the two bevel gear rims ( 15 ,  15 ′) of the two double gear wheels ( 18 ,  18 ′) and arranged on the side of the wobble plate facing away from the third gear wheel. 
     
     
         5 . The steering gear as set forth in  claim 1 , wherein each of the first gear rack-and the second gear rack are extensively and elongately cuboid, wherein the corresponding first end toothing and the second end toothing is present along a first longitudinal end face, and the corresponding first and second lateral toothings, which meshes with the respective first and second drive pinions, perpendicular to the end toothing along a side face. 
     
     
         6 . The steering gear as set forth in  claim 1 , wherein the steering gear includes a bearing plate with a respective guide device for each of the first and the second gear racks, with each of the first and the second gear racks being mounted in its assigned guide device so as to be longitudinally mobile perpendicular to the common axis and, with the corresponding first and second end toothings, facing away from a top side of the bearing plate on which the first and second double gear wheels with the the first and second transmission pinions are arranged, wherein the first and the second motors are arranged on an underside of the bearing plate. 
     
     
         7 . The steering gear as set forth in  claim 6 , wherein the guide devices each are a respective guide groove located in the bearing plate and running perpendicular to the common axis, wherein a lower guide portion on the side of the corresponding first and second gear racks facing away from the respective first and second end toothings is accommodated in the corresponding guide groove, and/or
 the guide devices are provided by at least one guide block arranged on the top side of the bearing plate and having a lateral guide groove which runs perpendicular to the common axis, points to the respective gear rack, and accommodates a longitudinal rail present on a side face of the gear rack facing away from the side face with the lateral toothing.   
     
     
         8 . The steering gear as set forth in  claim 6 , wherein the respective side faces of the gear racks with the lateral toothing face the respective first and second double gear wheels. 
     
     
         9 . The steering gear as set forth in  claim 1 , wherein each of the first and second double gear wheels comprises a bevel gear with the bevel gear rim which is connected to the transmission pinion with toothing all around via a gear shaft which extends along the common axis. 
     
     
         10 . The steering gear as set forth in  claim 9 , characterized in that the gear shaft is rotatably mounted in a bearing eye component, wherein the bearing eye component is fastened to the bearing plate and aligned in relation to the axis of rotation of the respective first and second double gear wheels mounted in the bearing eye component with the gear shaft. 
     
     
         11 . A surgical instrument comprising:
 a shaft, an actuation unit arranged at the proximal end of the shaft, and an instrument arranged at the distal end of the shaft and having a tool tip which is able to be angled by means of a distal angling mechanism and controllable by a wobble plate that is spatially alignable by means of two drives, wherein the surgical instrument further includes the steering gear as set forth  claim 1 , the configured to transfer the adjustment angles of the two motorized drives to the spatial alignment of the wobble plate.   
     
     
         12 . The surgical instrument as set forth in  claim 11 , further including a third gear wheel that meshes with the first and the second bevel gear rims of the first and the second double gear wheels, the wobble plate, via a bearing ring, is mounted so as to be rotatable about the longitudinal axis of the shaft in a steering ring that is coupled for conjoint rotation with the third gear wheel, the wobble plate being a gimbal-coupled to a main shaft running coaxially to a longitudinal axis of the shaft. 
     
     
         13 . The surgical instrument as set forth in  claim 11 , wherein the wobble plate is pivotably mounted on a universal joint plate by way of two bearing pins arranged offset from one another by 180°, wherein the universal joint plate is pivotably mounted on the main shaft by way of two bearing pins arranged offset from one another by 180°, and wherein the bearing pins ( 27 ,  29 ) of the wobble plate and universal joint plate are arranged offset from one another by 90°, or
 a gimbal mount is provided by two longitudinally extending guide grooves diametrically present in the main shaft and two diametrically and radially inwardly pointing pins arranged on the wobble plate, wherein each pin engages in one of the guide grooves such that a rotary angle of the main shaft is transferable to the wobble plate. 
 
     
     
         14 . The surgical instrument as set forth in  claim 11 , wherein a fourth gear wheel is coupled to the wobble plate via a bearing ring with the steering ring, wherein the fourth gear wheel is freely rotatable vis-à-vis the third gear wheel. 
     
     
         15 . The surgical instrument as set forth in  claim 11  further including an actuation element that is axially displaceably mounted in the shaft and is operatively connected to the actuation unit on the proximal side, and in that the distal angling mechanism of the tool tip which is able to be angled consists of pivot members which are arranged at the distal end of the shaft and connected to the steering gear by way of steering wires running in the longitudinal direction of the shaft.